In the present study, we conducted all assessment and training of both parents and children entirely online to examine the effectiveness of an online parental coaching programme in facilitating young Filipino children's language, literacy, and numeracy skills. Ninety-four families with 3-to 5-year-old Cebuano-speaking children were randomly assigned into either the intervention group or a waitlist control group. The 13-week long online intervention group showed significant improvement in their receptive vocabulary, syllable matching, letter name knowledge, numeral identification, object counting, rote counting, missing number identification, numerical magnitude comparison and addition skills but not in their expressive vocabulary and syllable deletion relative to the waitlist control group. No moderation effect of socioeconomic status (SES) on the online intervention outcome was found. For the intervention group, a main effect for parental involvement on rote counting, missing number identification, and addition was found, with higher levels of participation in the coaching programme translating to greater gains. The present study underscores the validity and feasibility of an online format of intervention and assessment procedure, in a low-to-middle-income country context (LMIC). The current findings demonstrate the possible added benefits of an online intervention format and the importance of an integrated cross-domains intervention format.